Compressor and compressor valve



Avril 15, 1947. i A. F. SANDERS COIPRBSSOR AND COITYRESSOR VALVE Yund sept. e.' 194:5`

- when the pressure inthe compressor is such that vthe receiver to which the compressor delivers.

should be directed to the following description in l it closed thereafter. The closing may be effected Patented Apr. is, i947l Y ggwet;

srarssrATsNT saisies @UMRESSOR AND COMPRESSOR VALVE Arthur Freeman Sanders, Leeds, England Application September 8, 1943, Serial No. 501,582

In Great Britain September 26, 1942 6 Claims. (Cl. 230222) 1 The ordinary reciprocating compressor has an' outwardly by a spring I8, its head coasting with outlet or transfer valve which should be opened a cam 2o on a shaft 2i. for a. considerably less period than the exhaust Preferably, I provide a bleed hole 23, for the valve of an internal-combustion engine, .and hydraulic uid, which can act as a safety valve which should preferably be opened at a. moment 5 should the valve I4 be seated before the end of the plunger stroke or before the operating pressure is released. If desired, the arrangement may be such that the bleed hole is only uncovered My main object is to provide an improved form by the valve stem when the valve is almost opof transfer valve for use in a reciprocating comerated, e. g., closed. presser, but the invention is not limited in this One object of the invention is to provide means respect. for the abnormally rapid closingof the transfer For a better understanding oi this and other valve. Due to the high speed of closure and the objects and advantages of the invention attention additional closure force of the excess of pressure in the receiver over that in the compressor as the compressor piston is returning on the suction stroke, l. e., at the beginning of that stroke, there elevation of atransfer valve and actuating means, is a tendency for the valve to strike the valve seating with high velocity. It is therefore according to the invention, for a reciprocating compressor. I 20 very desirable to make the valve seating of some The invention broadly consists in a. reciprocatstiff resilient material of high internal friction. ing compressor having an outwardly-opening It is conveniently in the form o1 a simple cushion poppet valve which is positively moved in the Valve Seat bonded t0 en oilamiv heatcressline closing direction in timed relation to the com- Synthetic rubber. pre'ssor, the receiver pressure serving for holding 25 In operation, the arrangement is such that the pressure in the receiver to which the compressor :by cam or other actuating means acting on the delivers (i. e., in the receiver passage I5) will valveA stem through a hydraulic device. If the assist in the final closing of the valve Il and in plunger of the latter is of greater cross-section maintaining the valve closed. The cam means thanthe cross-section of the valve stern, the v preferably gradually releases the operational stroke of the valve will be proportionately greater than the eiective stroke of the plungeri. e., the

there will be little or `no resurgence of gas from whichV reference is made to the accompanying drawing the single ligure of which is a sectional seen from the shape of the cam at 21. A bleed valve can -be closed in less time for a. given actuh01--f01` exemple, @het merkd 23u-Will allow ating means than if the latter acted directly the return ow of uld as the plunger is being upon the valve stem. The plunger and valve stem Withdrawn.

need not be aligned with one another. The actu- The plunger is shown as coacting-ln a known ating means may include a cam acting directly Way With DOUBS 29 through Which a reservoir 3@ upon the plunger or indirectly thereon through for the hydraulic iiuld communicates with the a rocker, the plunger being springretumed in space below the plunger when the latter is at out either case, or, alternatively, in order to avoid centre, the bleed hole 23 communicating with this the necessity for the use of springs in the case reservoir. The pressure therein may be mainwhere high speeds may be involved, it may take tained by a pump (not shown), excess fluid being returned to the inlet side of the pump, also in e.

the form of an eccentric the strap of which actuknown manner. The ports are arranged in such etes the lun er sitivel in both directions.

p s po y manner that the inward motion of the plunger In the construction shown in the drawing, the reciprocating piston Il of the compressor works sets up no appreciable Nessun in its cylinder within a cylinder I2 I3 is a normal :om of bore until lit is closing the ports. Thereafter the valve stem is subject to pressure which brings inlet valve and u an outwardly'opemng-poppet the valve It on to its seating or preferably very valve for transferring the compressed an' from 50 close thereto. The timing of the closing of the the Cylinder t0 the receiver passage 5- The' valve is sensibly lfixed by the plunger reaching its Valve Stem s Operates in the Smaller bore 0f a irl-centre, as shW-n 0r alternatively, by uncnv- Valve guide having a 1818er bore in which a ering arelief port in its cylinder barrel, whereby plunger I1 operates, and between the two is hythe operational pressure on the valve stem is draulic liquid I8. The plunger is shownas pressed ended-this latter arrangement not being illus'- (i. e., closing) pressure on the plunger, as will be trated but being Well known in connection with fuel pumpatorfinjection engines. Preferably, the operational pressure on the plunger will be completely withdrawn-well before m the compressor pressure will in ordinary conditions have reached the receiver pressure, so that the transfer valve can open as pressure conditions in compressor and receiver permit, and so open earlier than will -be demanded in-ordinary conditionsjwhen this should be necessary-for example, when first star-ting up. The valve may open towards the, end of the withdrawal stroke of the plunger, while the latter is fully with'- drawn. or during the beginning of the operational stroke of the plunger, and the free end of the latter remote from the cam means is' preferably provided with a recess32 to receive the end of thevalve stem'with slight clearance, so that if the plunger should be engaged upon its operational stroke a friction buffer effect would be provided (when the plunger might otherwise make direct contact with' the stem) when the valve is iirst being accelerated in the closing direction.

In the case oi a reciprocating compressor for ing said plunger to the position corresponding supercharging a compression-ignition engine operating with fue] injection, I may use fuel oil as the hydraulic uid, as any leakage of fuel oil would be carried through into the receiver and subsequently used inthe engine.

What I claim as my invention and desire to secure by Letters Patent' of the United States is:

1. In a reciprocatingcompressor, a receiver passage for compressed iiuid, an outwardly opening poppet valve for passing compressed fluid from said compressor to said receiver passage,

said valve having the external surface of its head exposed to the pressure inlsaid receiver passage, means for positively moving said valve in the closing direction in timed relation to said compressor, and a hydraulic travel increasing device interposed between said valve closing means and the valve stem for enhancing the closing speed of said valve.

2. An arrangement according. to claim 1 in which said hydraulic device comprises a hydraulic cylinder, a piston constituted by the valve stem received in a bore of said cylinder, a plunger of greater cross-sectional area than said valve stem received in a corresponding bore in said cylinder and acted upon by said valve closing means to close said valve at a greater speed than that imparted to said plunger, and means for restorwith the open position of said valve.

3. In a reciprocating compressor, a receiver passage for compressed fluid, an outwardLv opening poppet valve for passing compressed fluid from said compressor to said receiver passage, said valve having the external surface of its head exposed to the pressure in the receiver passage, a hydraulic cylinder, a piston constituted by the valve stem received in a bore of said cylinder; a plunger of greater cross-sectional area than that of said valve stem received in a, corresponding bore in said cylinder, means for positively moving said plunger in the direction for it to close said valve at a speed greater than that imparted to said plunger and in timed relation to the compressor,

means for restoring said plunger to the position corresponding with the open position of said valve, a hydraulic reservoir, and means for providing' a. communication between said hydraulic cylinder and reservoir to permit said plunger to respond to the restoring means While said valve is closed.

4. An arrangement according to claim 3 in which the hydraulic cylinder is ported in a position that permits the escape of hydraulic uid to the hydraulic reservoir until said plunger nears the inner end of its stroke and closes said port.

5. An arrangement according to claim 3 comprising a recess in the end of said plunger adapted to receive the adjacent end of the valve stem with clearance and thereby, in conjunction with the hydraulic fluid, to provide a cushion buier.

' 6. An arrangement according to claim 3 comprising a resilient damper seating for the valve. ARTHUR FREEMAN SANDERS.

'REFERENCES CITED The'followlng references are of record in the le of this patent:

'. UNITED STATES PATENTS Number Name Date 1,925,544 Rix Sept. 5, 1933 1,878,326 Ricardo Sept. 20, 1932 ,1,609,284 Barbarou Dec. 7, 1926 1,096,828 Conrad May 19, 1914 2,011,780 Staley Aug. 20, 1935 FREIGN PATENTS Number Country Date 4,403 British 1891 

